From e02e345a288c5c0bfbd38a28d61b209ecbfb4297 Mon Sep 17 00:00:00 2001
From: Nathan Strong <gblues@gmail.com>
Date: Tue, 5 Oct 2021 15:42:25 +0000
Subject: [PATCH] Make GCA driver compatible with other HID drivers

== DETAILS
Use a little trickery to ensure the GCA driver continues working
with other HID implementation.

I've expanded the joypad implementation to support multi-pad devices.
However, this requires changes to each HID implementation to actually
function.

I've made the necessary changes for WIIU, but I don't have the means
of making the change in the other HID implementations.

So, I've built in a backwards-compatibilty mode for the driver.

The trick is to have an identifier byte at the top of both data structs
that the driver returns. We can then use that byte to determine which
of the structs has been passed to the pad functions and act accordingly.

In the GCA case, for non-wiiu platforms, it will simply expose port 1
of the GCA and the other 3 ports do nothing.
---
 input/connect/connect_wiiugca.c | 35 +++++++++++++++++++++++++++------
 input/input_types.h             |  2 +-
 retroarch.c                     |  2 +-
 3 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/input/connect/connect_wiiugca.c b/input/connect/connect_wiiugca.c
index 784bbc5d15..2e8bd45615 100644
--- a/input/connect/connect_wiiugca.c
+++ b/input/connect/connect_wiiugca.c
@@ -24,6 +24,9 @@
 
 #define GCA_MAX_PAD 4
 
+#define GCA_TYPE_DEVICE 0x00
+#define GCA_TYPE_PAD    0x01
+
 #define GCA_PORT_INITIALIZING  0x00
 #define GCA_PORT_POWERED       0x04
 #define GCA_PORT_CONNECTED     0x10
@@ -34,6 +37,7 @@ typedef struct hidpad_wiiugca_data gca_device_data_t;
 
 struct hidpad_wiiugca_pad_data
 {
+   uint8_t datatype;
    gca_device_data_t *device_data;
    joypad_connection_t *joypad;
    int pad_index;
@@ -44,6 +48,7 @@ struct hidpad_wiiugca_pad_data
 
 struct hidpad_wiiugca_data
 {
+   uint8_t datatype;
    void *handle;
    hid_driver_t *driver;
    char connected[GCA_MAX_PAD];
@@ -76,6 +81,7 @@ static void* hidpad_wiiugca_init(void *data, uint32_t slot, hid_driver_t *driver
 
    device->handle = data;
    for(i = 0; i < GCA_MAX_PAD; i++) {
+      device->pad_data[i].datatype = GCA_TYPE_PAD;
       device->pad_data[i].device_data = device;
       device->pad_data[i].joypad = NULL;
       device->pad_data[i].pad_index = i;
@@ -99,9 +105,13 @@ static void hidpad_wiiugca_deinit(void *device_data)
 static void hidpad_wiiugca_get_buttons(void *pad_data, input_bits_t *state)
 {
    gca_pad_data_t *pad = (gca_pad_data_t *)pad_data;
-   if (pad)
-   {
-      BITS_COPY16_PTR(state, pad->buttons);
+   if (pad) {
+      if(pad->datatype == GCA_TYPE_PAD) {
+         BITS_COPY16_PTR(state, pad->buttons);
+      } else {
+         gca_device_data_t *device = (gca_device_data_t *)pad_data;
+         BITS_COPY16_PTR(state, device->pad_data[0].buttons);
+      }
    }
    else
    {
@@ -119,7 +129,12 @@ static int16_t hidpad_wiiugca_get_axis(void *pad_data, unsigned axis)
    if (!pad || axis_data.axis >= 4)
       return 0;
 
-   return gamepad_get_axis_value(pad->analog, &axis_data);
+   if(pad->datatype == GCA_TYPE_PAD)
+      return gamepad_get_axis_value(pad->analog, &axis_data);
+   else {
+      gca_device_data_t *device = (gca_device_data_t *)pad_data;
+      return gamepad_get_axis_value(device->pad_data[0].analog, &axis_data);
+   }
 }
 
 static void update_button_state(gca_pad_data_t *pad) {
@@ -227,7 +242,7 @@ static void hidpad_wiiugca_set_rumble(void *data,
 const char *hidpad_wiiugca_get_name(void *pad_data)
 {
    gca_pad_data_t *pad = (gca_pad_data_t *)pad_data;
-   if(!pad) {
+   if(!pad || pad->datatype != GCA_TYPE_PAD) {
       return DEVICE_NAME;
    }
 
@@ -246,7 +261,15 @@ const char *hidpad_wiiugca_get_name(void *pad_data)
 
 static int32_t hidpad_wiiugca_button(void *pad_data, uint16_t joykey) {
    gca_pad_data_t *pad = (gca_pad_data_t *)pad_data;
-   if (!pad || !pad->device_data || joykey > 31 || pad->joypad == NULL)
+
+   if(!pad) return 0;
+
+   if(pad->datatype != GCA_TYPE_PAD) {
+      gca_device_data_t *device = (gca_device_data_t *)pad_data;
+      pad = &device->pad_data[0];
+   }
+   
+   if (!pad->device_data || joykey > 31 || pad->joypad == NULL)
       return 0;
 
    return pad->buttons & (1 << joykey);
diff --git a/input/input_types.h b/input/input_types.h
index 141ea1830a..235bae2626 100644
--- a/input/input_types.h
+++ b/input/input_types.h
@@ -107,5 +107,5 @@ typedef struct rarch_joypad_info rarch_joypad_info_t;
 typedef struct input_driver input_driver_t;
 typedef struct input_keyboard_ctx_wait input_keyboard_ctx_wait_t;
 typedef struct turbo_buttons turbo_buttons_t;
-
+typedef struct joypad_connection joypad_connection_t;
 #endif /* __INPUT_TYPES__H */
diff --git a/retroarch.c b/retroarch.c
index 25e106f68b..9f53e99ad7 100644
--- a/retroarch.c
+++ b/retroarch.c
@@ -15437,7 +15437,7 @@ const char* config_get_joypad_driver_options(void)
 void *hid_driver_get_data(void)
 {
    struct rarch_state *p_rarch = &rarch_st;
-   return p_rarch->hid_data;
+   return (void *)p_rarch->hid_data;
 }
 
 /* This is only to be called after we've invoked free() on the